The topic of micro- and nanoplastics (MNPs) has become increasingly prevalent over the past years, as amidst dismissal and panic, researchers attempt to distinguish just how much of a problem MNPs truly are. The most essential problem here is that we are still developing the tools to accurately measure the levels of MNP contamination. Recently, [Madeline E. Clough] et al. demonstrated in an article published in Analytical Methods how gloves worn in laboratory settings can create false positive MNP signals.

As we covered previously, detecting MNPs is tough due to the detection methods used, many of which rely on interpreting signals from methods like pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), with protocols for this and other methods still being worked on, particularly on how to filter out false positives.

The article by [Clough] demonstrates how dry contact of lab gloves on samples can deposit stearate salts – left over from their production, which are subsequently misidentified as being MNPs, specifically polyethylene (PE). These false positives occur with µ-Fourier transform infrared (µ-FTIR) spectroscopy and µ-Raman spectroscopy, but can occur with Py-GC-MS as well, as has been determined previously. Substances like the fatty lipids that are commonly found in the human body, and in particular the brain, will closely match the PE signature.

With these very common stearate salts now also a likely source of contamination with MNP measurements, it just becomes more obvious that it’s incredibly hard to make accurate assessments about any hazards of MNPs until we can determine their presence with any level of reliability.